The Met Office has rissued a health warning as temperatures are set to reach 30C this weekn.
The forecaster had previously issued a Heat Health alert Level Two warning – but this has now been raised to three for the south east.
The ‘Amber’ level three warning urges people take ‘heatwave action’ and is triggered when the Met Office confirms threshold temperatures for one of more regions have been reached for one day and the following night, and the forecast for the next day has a greater than 90 per cent confidence level that the day threshold temperature will be met.
“This stage requires social and healthcare services to target specific actions at high-risk groups,” says the Met Office.
Health authorities are encouraging those most vulnerable – many of whom have been shielding during the lockdown – to protect themselves amid the “exceptionally hot weather forecast this week”.
Public Health England (PHE) said older people, those with underlying health conditions, and very young children were all more at risk from the higher temperatures.
People have been advised to keep cool and stay hydrated where possible.
The mercury is expected to hit the low-30s in the south of England before Friday and warnings have been issued about UV levels, which are going to be “exceptionally high” over the next few days.
Emer O’Connell, consultant in public health at PHE, said it was important that people kept checking on the vulnerable, as many continued to spend more time at home due to coronavirus.
“You will need to do things differently this year, for example keeping in touch by phone,” she said.
“If you need to provide direct care to someone at risk from hot weather, follow Government guidance on how to do this safely.
“The most important advice is to ensure they stay hydrated, keep cool and know how to keep their homes cool.”
Health minister Jo Churchill said people could take simple steps to keep themselves safe.
She said: “Apply sunscreen regularly, stay hydrated, and protect your head from the sun.
“Look out for those who are vulnerable in the heat, and provide support where needed, continuing to follow social distancing guidance.”
Advice from the Met Office included closing curtains on rooms that face the sun to keep indoor spaces cooler, avoiding excess alcohol and dressing appropriately for the weather.
St John Ambulance said this could mean wearing light clothes to keep your skin covered and protected in the sun, as well as wearing high-factor sunscreen.